Sulphur deficiency in soils and crop response to fertiliser sulphur in India

Abstract

Soil health has become a cause of concern for sustainable agricultural production in the new millenium. Use of high analysis sulfur free fertilizers, heavy S removal by the crops under intensive cultivation and neglect of S replenishment has contributed to widespread sulphur deficiencies in India. Over 27000 soil samples from 12 states were analysed, of which 40% were found deficient and anther 35% were potential deficient in available sulphur. More than 70% soil samples taken from Uttar Pradesh, Madhya Pradesh, Maharastra, Orissa, Jharkhand, West Bengal , Andhra and Karnataka were found low to medium in available sulphur. High crop response to applied sulphur was observed. The optimum sulphur dose varied between 30-45 kg/ha. The rice yield increased by 5-51%, maize by 11-93%, wheat by 29-30 % and sorghum by 14%. Amongst the oilseeds, the yield increase was 13-69% in groundnut, 19-34% in mustard, 10-100% in soybean and 60% in sunflower. Amongst pulses, it was 44% in pea and 20% in cowpea. Across the crops and region, the agronomic efficiency varied from 6-30 kg/kg applied sulphur and apperant sulphur recovery from 2-27%. The residual effect on succeding crops varied from 3-81%. The economic returns from S fertilizer application were very attractive. The value cost ratio (VCR) ranged between 12-24.